1. Field of the Invention
The present invention relates to a culture medium for the fetus-derived mesenchymal stem cells in amniotic fluid. More particularly, the present invention relates to a composition for improving skin conditions, comprising the culture medium of the fetus-derived mesenchymal stem cells in amniotic fluid as an active ingredient, in which the skin conditions include whitening, wrinkles, skin damages caused by UV rays or skin lifting. Further, the present invention relates to a method for preparing the composition, comprising the steps of culturing the fetus-derived mesenchymal stem cells in amniotic fluid; and collecting the culture medium.
2. Description of the Related Art
Stem cells have an ability to differentiate into a variety of cells by appropriate environment and stimulation and also have a self-proliferating ability. There are three types of stem cells: embryonic stem cells (ES cells) isolated from the early embryo, embryonic germ cells (EG cells) isolated from primordial germ cells at an embryonic stage, and multipotent adult progenitor cells (MAPC cells) isolated from adult bone marrow. Stem cells have the potential to develop into cells that have unique phenomena and specialized functions, and thus they have been proposed as an attractive cell source for regenerating various organs.
Until now, adult stem cells have been known to have the ability to differentiate into various cells. Adult stem cells were isolated from the bone marrow (Science 276, 71-74, 1997; Science 284, 143-147, 1999; Science 287, 1442-1446, 2000), the skeletal muscle (Proc. Natl Acad. Sci. USA 96, 14482-14486, 1999; Nature 401, 390-394, 1999), and the fat tissue (Tissue Eng 7, 211-228, 2001; J. Cell. Physiol. 206, 229-237, 2006), and each of them is able to differentiate into similar cell lineages.
Bone marrow-derived mesenchymal stem cells are adult stem cells that have been used for a long time, and their efficacies were also proved. In addition, recent studies have reported that the cells isolated from fat tissue or other tissues also have similar characteristics to the bone marrow-derived mesenchymal stem cells. However, it is difficult to isolate and purify a large amount of mesenchymal stem cells, and thus other alternative sources are urgently needed.
Therefore, the present inventors have focused on amniotic fluid that can be easily separated without any risk to the baby or its mother.
A few days after implantation of the fertilized egg to the uterine wall, the embryo is surrounded by the amniotic sac filled with amniotic fluid. Since the amniotic fluid contains a lot of materials excreted by the fetus, chromosome abnormalities of the fetus or bacterial infection can be tested in the amniotic fluid. In addition, amniotic fluid allows for easier fetal movement, protects the fetus from any outside impact and stimulation, prevents bacterial infection, and helps to regulate the fetal body temperature.
Before birth, information about the fetal health can be obtained through examination of the amniotic fluid. At this time, amniotic fluid can be collected throughout pregnancy without any risk to the mother. The cells used in the examination are discarded after examination, and can be used for research purposes under the patient's consent. Therefore, amniotic fluid-derived stem cells possess an advantage over other adult stem cells, because a large amount of cells can be easily obtained. At present, there are no reports whether the addition of a medium, obtained by culturing the fetus-derived mesenchymal stem cells in amniotic fluid for a predetermined period, affects the growth of fibroblasts.
The present inventors have isolated mesenchymal stem cells from the fetus in amniotic fluid and investigated their characteristics. Further, they have investigated components present in a conditioned medium that is prepared using the fetus-derived mesenchymal stem cells in amniotic fluid, and demonstrated effects of the conditioned medium in fibroblasts. Furthermore, the present inventors have demonstrated effects of the conditioned medium composition on skin elasticity and regeneration through a mouse in vivo test and a clinical test, thereby completing the present invention.